The A’s Khris Davis singles against the Giants in a game last June. (Nhat V. Meyer/Bay Area News Group)

Across the back of A’s left fielder Khris Davis is a tattoo of a B-2 stealth bomber.

The B-2 was a high-altitude, long-distance fighter plane, designed with a singular goal in mind: doing its job while remaining invisible.

“He’s a stealth ballplayer, and really always has been,” said Larry Eubanks, Davis’ coach at Deer Valley High in suburban Phoenix. “He’s a warrior and a guy you always wanted on your side, but he’s always cherished that under-the-radar ethos.”

Davis took Deer Valley to the Arizona state title in 2006, scoring the winning run in extra innings with a leadoff single and steal of second before coming around to score the walk-off run.

He was Arizona co-player of the year, but at the Deer Valley awards banquet, Eubanks said Davis was uncomfortable with others talking about him. He’d rather they talked about someone else. And that hasn’t changed much in the last decade.

“What I like about the stealth bomber,” Davis says, “is the stealth part. It does its job under the radar. I like being under the radar, too.”

So how’s that going to work now after last year’s 42-homer coming out party?

“Well, I don’t know that’s happening this year,” he said with a shrug. “There are no secrets in the big leagues. You can only stay quiet so long, and then you can’t.”

As a personality, Davis does like the quiet. As a ballplayer, he makes noise — huge noise.

The dichotomy can be explosive.

“My family says I’m like a monster right now,” he said. “They don’t know me when I’m on the field. When I’m on the field, it’s almost like I don’t know who my family is. I hear everybody trying to get some kind of reaction out of me. ‘Khris. Khris!’ they yell.

“I mean, I have to go a dark place I don’t know. It’s like a blackout scene, basically. It takes years of practice. It’s a mental thing. It’s like a mental edge.”

Although Davis honed that skill in college and as a pro, Eubanks recalls that dark place in evidence even in high school.

“We were playing a big rival, and a parent went out behind the center field fence and began yelling at him,” Eubanks said. “He was doing all he could to get Khris out of the game. The guy was maybe 40 feet away from him, and Khris never moved. I don’t think he even heard him. He had that ability. That’s very Khris.”

The darkness, the monster, the blackout? That doesn’t sound like a place most of us would like to go, even to be a Major League Baseball player.

For Davis, it’s his happy place.

“I love myself in that zone,” he said. “It’s therapeutic. Everything that’s going on outside the field, it blacks out. It’s almost meditative.”

It’s different, but then most things about Davis are. At 5-foot-11 and 192 pounds, it makes little sense how the ball comes off his bat as if shot out of a bazooka.

“Khris was the best high school hitter I’ve ever seen,” said Tommy Eubanks, Larry’s son and the outfield coach at Deer Valley in that title season. “The power you see has been there as long as I can remember. I think he hit a homer in five of the six games we played in the state tournament.

“We’re playing in spring training parks, and he’s hitting the ball out to left center, 50 or 100 feet beyond the well. His power was on another level.”

* * *

After high school, Davis spurned offers to go to Arizona State just down the road or the University of Arizona, a little farther down the road. Instead he went to Cal State Fullerton, not a big-name national athletics power except for baseball.

“We all know what kind of power he has now,” said George Horton, Davis’ first coach at Fullerton. “He showed signs of that kind of power with us. He’s an athlete, a naturally strong athlete.”

Davis’ size is sometimes seen as a reason why he shouldn’t have great power. His body type isn’t a beast in the sense of a Mark McGwire, Jose Canseco, Barry Bonds or Alex Rodriguez.

It turns out home run hitters don’t have to be. Those who have watched baseball through the prism of weight rooms and steroids have gotten used to the slugger as the Hulk. It hasn’t always been like that.

Davis’ body type shows him to be a throwback to the legacy of Willie Mays (5-10, 170) and Hank Aaron (6-0, 180), men who defined power in a different century.

“It didn’t used to be uncommon for guys his size to do this,” said Rodney Davis, Khris’ father and a former minor league player and baseball scout. “Mays, Aaron, those guys weren’t all that big, but nobody had more power.”

Ask where the power comes from, Khris Davis sticks out his arms.

“It’s my hands,” he said. “I spent a lot of time hitting as a young kid.”

How much time?

“I had to sacrifice a lot of social aspects to play baseball the way I wanted to,” Davis says of his high school years. “I was always hitting, taking swings, getting stronger, working on the game.”

Jaff Decker, now an outfielder in the A’s organization, is a lifelong Davis friend. He was the opposing pitcher when Davis scored to beat Sunrise Mountain for the state title.

“You have never seen anybody work so hard as Khris did,” Decker said. “He was always hitting, always working on getting better. And he kept getting stronger. After he left Deer Valley, I went and saw him at Fullerton and I couldn’t believe how he looked. He’d grown into his man body.”

A’s shortstop Marcus Semien was the only Oakland player other than Davis to hit more than 17 homers last year. It’s Semien’s belief that just looking at Davis’ height and weight is missing the point.

“I think it’s wrong to focus on his size without looking at his legs, shoulders and arms. He’s not tall, but he’s got huge legs and a great upper body,” Semien said. “There was a lot of head-shaking in our dugout at some of the balls he hit last year. There was one opposite field homer in Anaheim that looked like a left-handed pull hitter had crushed it. There was another in Detroit that hit the brick wall in left-center. That’s amazing.”

* * *

Nothing that Davis has done has come as a surprise to Doug Melvin. He was the general manager in Milwaukee in 2009 when the Brewers took Davis with their seventh pick.

“In today’s game, some hitters get in hitter’s counts and get passive,” Doug Melvin said. “That was never Khris. He’s aggressive, aggressive always.

“He’s very poised in the batters box and relaxed as a hitter. It’s the relaxed part of him that turns into aggressiveness at the plate. He doesn’t get flustered. He’s never out of whack. He’s a fighter.”

Talk to enough people about Davis, and the word fighter is bound to crop up. “Warrior” or “soldier” will show up, too.

“He’s always enjoyed a soldier’s mentality,” Rodney Davis says. “He’d go to airshows when he was a kid. He admires that fighter’s mentality. And that’s the place he goes to play baseball, to soldier up.”

Tommy Eubanks said even as a high school player, Davis would not just soldier up himself. He’d bring the rest of his teammates together to go to war collectively.

“He has the kind of confidence that isn’t cocky,” Tommy Eubanks said. “It’s the kind that makes everybody else confident, too. He consistently had that, game to game, one of the reasons we did what we did in winning the title.”

Asked to explain, Davis said it’s the warrior in him coming out.

“It’s the competitor in me. I want to win, that’s what matters to me,” he said. “I would challenge my teammates to compete and not get caught up in rankings and all that other bull. It’s only about winning the game. I thought I did a good job. I thought I was a leader in my group in not giving a damn about who has what reputation. I just kept quiet and got after it.”

Davis isn’t one who thinks much about the past. He says 2016’s power show is over, that 2017 will be its own entity.

The exception to that forget-the-past attitude is the 2006 Arizona State high school championship. That looms transcendent in Davis’ memory. He wants a repeat, to feel that rush, this time with the A’s. He knows not only what he has to do, but what he needs in the lineup around him.

“I can only speak for myself” Davis said. “I can only say I need someone to hit .300 in front of me. I need protection in the lineup. For myself, I need to carry my weight. I need to hit, be a weapon at the plate. And defensively I need to take away hits and not give the other side extra bases. I need to be a great teammate, be a good vibe. I can’t predict what the front office will do.”

What he can predict is that he expects the A’s of 2017 to be better, substantially better, than recent vintages.

“I think having a healthy team here, first and foremost, is important,” he said. “If we do that, we’re going to be as competitive as we allow ourselves to be. We might surprise ourselves. I hope so.”